In an EVPN network, a service provider network may provide multi-homed service (e.g., to provide network, node-, link-, and port-redundancy for service providers) to customer networks via provider edge (PE) devices (e.g., router or switches) located at an edge of the service provider network. Aliasing can occur where a customer edger (CE) device is multi-homed to multiple PE devices, and a remote PE device associatively linked to the CE device learns only a subset of the MAC addresses associated with the multiple PE devices. For a given Ethernet Segment (ES), this can lead to a situation where the remote PE device cannot effectively load balance traffic among the PE nodes connected to a multi-homed ES. Although standards such as RFC 7432 published though the IETF (Internet Engineering Task Force) provides for explicit aliasing operations that facilitate a remote PE device to send traffic to multiple peering PE devices of a given Ethernet Segment via ECMP (Equal-cost multi-path routing) (e.g., by explicitly signaling PEs that have reachability to given EVPN instance (EVI) on a given Ethernet Segment (ES) when the PE has not learned MAC addresses from that EVI/ES), the explicit aliasing operations is optional and employs transmission of an Ethernet Auto Discover (EAD) per EVPN instance (EVI) route (also referred to as a “per EVI/EAD route”). That is, a given manufacturer of a PE device may decide not to provide support use of per EVI/EAD route, resulting in incompatibility that can cause traffic to be transmitted to only a subset of the peering PE devices (i.e., in a non-ECMP manner) when ECMP (Equal-cost multi-path routing) is enabled. ECMP is a routing strategy where next-hop packet forwarding to a single destination can occur over multiple “best paths” per a defined routing metric. RFC 7432 “BGP MPLS-Based Ethernet VPN” is incorporated by reference herein in its entirety.
BGP (Border Gateway Protocol) is an inter-autonomous system routing protocol and is used to exchange routing information for the Internet, e.g., among Internet Service Providers (ISPs). BGP neighbors exchange routing information when a TCP connection between neighbors is first established. When a change to the routing table is detected, the BGP router send to its neighbors only those routes that have changed, and updates that are advertised include only the optimal path to a destination network.